It is known to introduce endovascular stent grafts into the vasculature of a patient to bridge an aneurism or damaged portion of the wall of the vasculature. Problems can occur, however, where the damage to the vasculature includes or is adjacent to a branch vessel from a main artery because the branch vessel may be occluded by the stent graft and cause permanent damage to the patient. Examples of such branch vessels are the renal and the mesenteric arteries extending from the aorta.
Fenestrations in a stent graft have been proposed to allow access to a branch vessel from a main stent graft but it is often necessary to provide a side branch graft to maintain access into the branch vessel. Catheterisation of such a branch vessel from a delivery device through the fenestration enables deployment of a covered stent or uncovered stent into the branch vessel. This invention provides an improved apparatus for catheterisation and deployment of side branch grafts.